A high speed precision metal cutting saw assembly is shown in U.S. Pat. No. 4,018,118, which is herein incorporated by reference, and includes a saw table and support frame manufactured to exceedingly close tolerances and on which a circular saw blade and its driving apparatus is suspended. The saw blade drive or arbor is mounted for horizontal translation together with its driving motor from one end of the table to the other within the interior of the saw table support frame. A stop plate which is adjustable to close tolerances is mounted on top of the saw table and provides an abutment for one edge of a work piece for precision positioning and cutting of the work piece by the saw blade. Additionally, a multiplicity of fluid operated clamps are provided to clamp a work piece in its proper cutting position and retain the work piece on both sides of the cut during the entire cutting operation.
The horizontal translation of the saw blade in the '118 patent includes two carriage ways which are positioned parallel and horizontally adjacent to one another. The saw blade arbor and carrier assembly are supported on and suspended between the carriage ways and move through the interior of the saw table framework. The translation of the carriage and arbor is provided by means of a pinion which engages a fixed rack adjacent to the carriage ways. Each carriage way is fixedly attached to opposite sides of the saw table frame structure. The work piece support surface includes two portions which are, also, mounted on opposite sides of the saw table frame and define a slot for the saw blade. Due to the size of the arbor and carriage assembly, the carriage ways are required to be separated by a substantial distance. The two portions of the workpiece support surface are cantilevered from their respective sides of the support frame and are extended from the frame by a relatively large distance so as to enclose the carriage and arbor assembly and support the workpiece. This structure effectively increases the size of the frame required to support the assembly and work piece and maintain them in position at the desired tolerances of the cutting operation and also limits the amount of clamping pressure which may be applied by the fluid operated clamps on both sides of the cut.
Another known metal cutting saw assembly similar to that shown in the '118 patent utilized two arbor and carriage structures so as to permit the assembly to cut both nonferrous metals, which typically require a relatively high blade cutting speed at a low torque, and ferrous type alloys, which typically require a lower cutting speed than that for cutting non-ferrous metals and have a high torque requirement for precision cutting. The carriage way arrangement utilized for this type structure utilized the two horizontal carriage ways similar to that shown in the '118 patent.
It was previously contemplated to provide two, substantially vertically positioned carriage ways in a dual material cutting saw, having two arbor and carriage assemblies. This arrangement, however, was believed to be unsatisfactory for proper support and stabilization at the desired precision tolerance range.
It was known to utilize one machine for cutting ferrous alloys and another for cutting non-ferrous metals such as aluminum and the like. Typically, the structures of these machines varied, such as the relative size of the table saw frame, the power requirements and saw blade motor speed, depending on the size of the work piece and type material being cut. Additionally, it was known to combine the two structures, as discussed above, so as to utilize two arbors and carriages having separate motors which were positioned on two carriage ways mounted on opposite sides of the frame work so as to cut metals of either the ferrous or non-ferrous type. These machines were built utilizing the more rigid frame as required for cutting the ferrous materials. The two arbors were switched manually so as to achieve the desired cutting operation.